Thenoyltrifluoroacetone dissolved

The ionization of Lr would be expected to stop with the f- core intact because of the enhanced binding energy of possible valence electrons in the filled f shell. The stable valence state of Lr would then be the (III) state. Experiments to confirm this oxidation state of Lr were undertaken by Silva and coworkers (1). They compared the extraction behavior of Lr with several tri- and tetravalent actinides and with Ba +, Ra +, and No +. A chelating extractant, thenoyltrifluoroacetone dissolved in methyl isobutyl ketone, was employed to extract the tracer ions from aqueous solutions that had been buffered with acetate anions. Their results, shown in Figure 8, very clearly demonstrate that Lr is extracted within the same pH range as the trivalent actinides, and therefore, proves that Lr is trivalent. 

In natural U, the radionuclides of the uranium family and the actinium family are present, and sometimes also radionuclides of the thorium family. Therefore, direct determination of U in ores without chemical separation is difficult, especially since the absorption of the radiation depends on the nature of the minerals. Generally, the samples are dissolved and Th is separated, e.g. by coprecipitation or by extraction with thenoyltrifluoroacetone (TTA). Radioactive equilibrium between " Th and the daughter nuclide 234mp jg rather quickly attained, and the high-energy yS" radiation of the latter can easily be measured. A prerequisite of the determination of U by measuring the activity of either " Th or 234mp jg establishment of radioactive equilibrium. This means that the uranium compound must not have been treated chemically for about 8 months. 

Thenoyltrifluoroacetone-xylene 0.5M. is prepared by dissolving 111 grams of the ketone and diluting it to 1 liter with C. P. xylene. (2-Thenoyltrifl.uoro acetone may be obtained from Graham, Crowley, and Associates, Inc., 5465 West Division St., Chicago 51, HI.)... 

Binnemans s group found that a high quantum yield and an enhanced photostabiUty are achieved for a Eu " tetrakis(2-thenoyltrifluoroacetonate) complex dissolved in a weakly coordinating 1-hexyl-3-methylimidazolium ionic liquid... 

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